Pump for mechanical refrigeration



@. agmwsm PUMP FOR MECHANICAL REFRIGERATION Filed 06%. :50, 1926 //2 en/or jw za Affar'nez s Patented a, 23, 1928.

I 1,688,890 UNITED STATES PATENT O FIC CHARLES C. SPREEN, OFD1311IlZtOI'l MICHIGAN, -ASSIG1\l'OR TO KELVINATOR CORPOR A- TION, OF'DETROIT, MICHIGAN, A CORPORATION OF MICHIGAN. J l

,PUMP. FOR MECHANICAL REFRIGERATION.

Application fi led October 30, 1926. Serial No. 145,157.

My invention relates to mechanical refrigeration, and particularly tocompressors for compressing the refrigerant 1n mechanical refrigerationunits, and'the particular "object of my invention is to providea new andimproved compressor of this type. In

the'drawings accompanying this specifica-' received and supported withinalined upper and lower annular surfaces 14 and 15 provided upon acompressor casing 16 extending outwardly intermediate the upper andlower annular faces 14 and 15 to provide between itself and the cylindersleeve 13 a refrigerant intake chamber 17 provided with an intakeopening 18 controlled by a suitable shutoff valve 19; and a compressorhead 20 forming the upper wall of the compression chamber 21, secured tothe'compressor casin by means of a plurality of bolts 22 exten in intoscrew-threaded apertures 23 forme about the upper portion of thecompressor casing 16, and itself comprising: a plate 24 directlyengaging the upper edge of the compressor casing 16, and the upper edgeof the cylinder sleeve 13, and provided with a central outlet opening25; and adome 26 surmounting the plate 24, provided with .an upperconvexed section 27 providing an out let chamber 28 in communicationwith the outlet opening 25 in the plate 24, having an outlet opening 29for the flow of the compressed refrigerant from the outlet chamber 28through a suitable shut-ofi valve 30, and containing within-the outletchamber 28 a suitable valve unit 31 herein shown as comprising a valveplate 32 yieldably held in position closing the upper end of the outletopening 25 of the plate 24 by means of a compressor spring 33 confinedbetween the upper face of the valve plate 32 and the lower face of theupper end of a yielding abutment 34 itself yieldably held in position bymeans of a compression spring 35 confined between the upper face of theupperend of the yielding abutment 34 and the lower face of the upper endof a fixed abutment 36 fixedly mounted in" position within thecompressor head 20, the .double valve mechanism being provided to permitabnormal opening of the valve for the passage of an unusualdischarg'efrom the compressing chamber 21, such as a slug of oil, or the like.

In the embodiment of my invention herein shown the piston 12 comprises abody 37, a head 38 secured to the upper end of the body 37 and formingthe movable wall of the compressing chamber 21, upper and lower skirts39' and 40 depending respectively from the head 38 and the body 37 andthemselves provided with alined upper and lower sur faces 41 and 42slidably engaging the inner surface of the cylinder sleeve 13, andabearing pin 43 mounted in the body 37 and receiving the connecting rod44 by which the piston 12 is reciprocated within the cylinder sleeve 13;the'piston head 38 is provided with a plurality of apertures 45communicating with a chamber 46 within the piston 12 in communicationwith the intake chamber 17 of the compressor casing 16 through a port 47in the cylinder sleeve 13, and through the ports 50 in the piston body37, and the crankcase 51; and the flow of refrigerant from the intakechamber 17 through the port 47, or the crank case 51 and ports 50, intothe piston chamber 46, andthen through the apertures 45 into thecompressing chamber 21, is controlled by a valve plate 48 overlying theapertures 45 andpermitting flow of refrigerant into the compressingchamber 21, but seating against the piston head 38 to prevent flow ofrefrigerant in the reverse direction from the compressing chamber 21back into the intake chamber 17. v

In addition, the compressor 11 herein shown is provided with a secondpassageway for the inflow of refrigerant into the compressing chamber21, comprising an extension of the port 47 providing communicationthrough the cylinder sleeve 13 from the intake chamber 17 directly intothe compressing chamber 21 at a point to be uncovered by the skirt 39depending from the piston head 38 only when the piston 12 is insubstantially its extreme retracted position.

From the above description those skilled in the art will understand thatwith the shut-off the compression chamber 21 valves 19 and in openposition, and the refrigerating apparatus in operation, the refrigerantwill flow through the shut-off valve 19 into theintake chamber- 17 andthe pistonchamber 46, and that during retraction of the piston 12 thisrefrigerant will flow additionally through the apertures45 intothecompressing chamber 21; that upon the beginning of the compressionstroke of the piston 12 the valve 48 will close the apertures 45 and thepiston 12 will compress the refrigerant within until it raises the valveplate 31 and flows-out through the outlet chamber '28 and outletshut-off valve 30; that during the final portion of the re- I tractionstroke of the piston 12 communication between the intake chamber and thepiston chamber f16 will be provided-additionally by the uncovering ofthe extension of the port 47 by the skirt 39 depending from the pistonhead 38, to thus permit, at this time,

' the flow of refrigerant into the compression chamber 21 directlythrough the cylinder sleeve 13, andto thus permit the valve 48 to seatslightly in advance of the beginning of the compression stroke of thepiston 12, to

thus insure that the valve 48 is fully seated at the beginning ofthecompression stroke of the piston 12; and that full charge ofrefrigerant into the compression chamber 21 is still permitted becauseof the passageway formed directly between the intake chamber 17 and thecompression chamber 21 by the extension of the port 47, and uncovereddurin the final portion of the retraction stroke 0 the pistOn 12.

Under these circumstances those skilled in the art will realize that Ihave provided a essee! compressor accomplishing at least the principalobject of my invention.

At the same time those skilled in the art .will realizethat theembodiment of my invention herein shown and described inc ud'esadvantagesother thanthose 5 ecifically referred to herein, and alsothatt is particular embodiment of m" invention may be variousl changedan modified without departing rom the spirit of my-invention orsacrificing the advantages thereof, and it will 7 therefore beunderstood that the disclosure herein is illustrative only, and that myinvention is not limited thereto.

I claim:

In a compressor for refrigerating apparatus a cylinder casing having anintake cham er encircling a portion thereof, a sleeve in said casinghaving intake ports extending in a direction axially thereof and in opencommunication with said intake chamber, a piston in said sleeve having aplurality of passages extending ,from the side wall and through the topw all thereof, said sleeve ports beingof greater lcngth than thedistan-ce'between the inlet end of said piston passages and the pistonend wall, and a movable valve associated with the piston end wall tocontrol the-passage of refrigerant through said piston, said pistonbeing arranged to uncover a CHARLES C. SPREEN.

